MAHBOD MOGHADAM: The best Ghostface song, I think, is " Nutmeg." That's all of his...

GREENE: That's Mahbod Moghadam. He and his friend Tom Lehman co-founded a Web site called Rap Genius.

MOGHADAM: Tom is here looking up...

TOM LEHMAN: These are my favorite lines of Ghost. It's from "Buck 50," where he says: supercalifragilisticexpialidocious, docialiexpilisticfragicalsuper Wu-Tang Chamber. Cancun catch me in the a room eating grouper...

(LAUGHTER)

GHOSTFACE KILLAH: (Rapping) Grouper. Grouper. Grouper...

LEHMAN: And so the explanation for that is on vacation, I'm actually eating fish is, which just doesn't fully cover...

MOGHADAM: I know, we have to refine this one...

GREENE: Think of Rap Genius as kind of like a Wikipedia for lyrics. Or, to use their metaphor, if hip-hop verse is our Scripture, they want to write the Internet Talmud.

LEHMAN: We're bringing the Talmud for the ADD generation. You know, like imagine if the great rap by Rom Bom was able to put animated GIFs, along with his exegesis of the Torah.

GREENE: This Web site, Rap Genius, harnesses the power of crowds to annotate verses. When you click on a lyric, a box pops up with text, photos and videos explaining the meaning. But Tom Lehman says they've always heard the same criticism.

LEHMAN: You know, how can you really say that you have the definitive explanation for the story behind a verse or a line, unless you get the artist involved?

GREENE: So they are getting artists involved.

(SOUNDBITE OF A SONG)

FABULOUS: (Rapping) I've been through a lot, wasn't looking for no cause...

I've been through a lot, wasn't looking for no cause, that's just wordplay, saying you've been through a lot in cars, you know, they own a car lot.

GREENE: Verified rappers, like Fabulous, now explain their lyrics on the site. And Rap Genius has bigger plans. It has annotated biblical verses and presidential debates. Last fall, a venture capitalist firm invested $15 million in this site. Lehman says the investors think the platform could be put to use in the classroom.

LEHMAN: You know, you could be a high school student and you're reading an annotation of "The Great Gatsby." Or you could be a graduate-level biologist and you're reading the annotations on a biology paper on the sexuality of fish.

GREENE: And the guys say they are in talks with Columbia University. They want freshmen to annotate "The Iliad and the Odyssey" on Rap Genius this fall.

(SOUNDBITE OF SONG, "DREAMS")

J COLE: (Rapping) I'm a genius in my dreams. Even if I was, it was stitched inside my genes...